Volume 27, Issue 2, pages 227-235, February 2012
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Authors: Cristina Tassorelli MD, PhD, Anna Furnari MD, Simona Buscone MD, Enrico Alfonsi MD, Claudio Pacchetti MD, Roberta Zangaglia MD, Anna Pichiecchio MD, Stefano Bastianello MD, Alessandro Lozza MD, Marta Allena MD, Monica Bolla MD, Giorgio Sandrini MD, Giuseppe Nappi MD, Emilia Martignoni MD
Abnormal postures of the trunk are a typical feature of Parkinson's disease (PD). These include Pisa syndrome (PS), a tonic lateral flexion of the trunk associated with slight rotation along the sagittal plane. In this study we describe clinical, electromyographic (EMG), and radiological features of PS in a group of 20 PD patients. All patients with trunk deviation underwent EMG and radiological (RX and CT scan) investigation. Clinical characteristics of patients with PS were compared with a control group of PD patients without trunk deviation. PD patients with PS showed a significantly higher score of disease asymmetry compared with the control group. In the majority of patients with PS, trunk bending was contralateral to the side of symptom onset. EMG showed abnormal tonic hyperactivity on the side of the deviation in the paravertebral thoracic muscles and in the abdominal oblique muscles. CT of the lumbar paraspinal muscles showed muscular atrophy more marked on the side of the deviation, with a craniocaudal gradient. PS may represent a complication of advanced PD in a subgroup of patients who show more marked asymmetry of disease and who have detectable hyperactivity of the dorsal paravertebral muscles on the less affected side. This postural abnormality deserves attention and proper early treatment to prevent comorbidities and pain.
© 2011 Movement Disorder Society
Summary and review by Leo Verhagen, MD, PhD, Associate Professor of Neurological Sciences, Rush University Medical Center, Chicago
Advancing Parkinson's disease can be associated with abnormal truncal postures. When the bending of the trunk occurs mainly in a forward direction the term camptocormia is used, whereas lateral bending is referred to as Pisa syndrome (PS). Most commonly these abnormal postures are considered a form of axial dystonia, but in some cases myopathic changes or skeletal deformities have been implicated, and more likely than not a combination of central and peripheral mechanisms is at play. The treatment of these disorders has remained elusive; anticholinergic therapy, botulinum toxin therapy and DBS may be of some benefit but overall the results are disappointing. In order to design better treatment modalities it is essential to improve our understanding of the underlying pathophysiology through clinical investigation.
The study by Tassorelli and colleagues in this issue of Movement Disorders aims to address this knowledge gap by characterizing Pisa syndrome in PD from a clinical, electromyographic and radiological point of view. Their study stands out because of careful patient selection, a relatively large number of patients (20) and the use of a control group of PD patients without truncal posturing. Of note, controls were only used to compare clinical variables but they did not undergo CT or EMG studies.
The authors found that, compared to controls, patients with Pisa syndrome had greater asymmetry of appendicular UPDRS items but similar scores on axial UPDRS items. In the majority (13/20) of patients bending was contralateral to the side of PD onset; in 5/20 the bending was ipsilateral, and in 2 patients PD onset had been bilateral. In 16/20 patients the lateral bending occurred over a 6 month period whereas in the remaining 4 patients it developed over less than one month. The average time to development of PS was 8 years. EMG obtained while patients were standing showed tonic hyperactivity of paraspinal muscles at T7-T10 levels on the bending side while EMG activity was reduced on the opposite side. CT scans of the paraspinal muscles of the lumbar spine revealed atrophy worse on the bending side, especially involving the multifidus and latissimus dorsi muscles.
Taken together, the authors suggest that PS in advanced Parkinson's disease may occur in a subgroup of patients who have marked asymmetry of PD symptoms and is associated with overactivity of paravertebral muscles on the bending, less affected side. Whether the increased lumbar paraspinal muscle atrophy on the same side is secondary or primary to the development of PS remains unclear.
The findings in this study are intriguing and should encourage further investigation into the pathophsyiology of PS and related disorders such as camptocormia, so that ultimately PD patients can be relieved of these dramatic and disabling truncal postures.
About Dr. Leo Verhagen
Leo Verhagen, MD, PhD, is a board-certified neurologist, an Associate Professor at Rush Medical College, and the Medical Director of the Neurosurgery Program for Movement Disorders, at Rush University Medical Center, Chicago, Illinois. He specializes in the medical and surgical management of patients with Parkinson's disease and other Movement Disorders such as Essential Tremor and Dystonia.